Optical multiband surface photometry of a sample of Seyfert galaxies. III. Global, isophotal, and bar parameters

TL;DR

This study provides detailed optical surface photometry parameters for Seyfert galaxies, including global, isophotal, and bar characteristics, revealing correlations and properties of bars within these galaxies.

Contribution

It introduces a homogeneous set of optical parameters for Seyfert galaxies, including novel bar length estimation based on profile and orbit analysis, and examines their correlations.

Findings

Median corrected isophotal colour indices: B-Ic=1.9, V-Ic=1.1 mag.

Bar length correlates with semi-major axis at 24 V mag/sq.arcsec.

Three large-scale bars are classified as strong based on ellipticity.

Abstract

This paper is third in a series, studying the optical properties of a sample of Seyfert galaxies. Here we present a homogeneous set of global (ellipticity, position angle, inclination, and total magnitude) and isophotal (semi-major axis and colour indices at 24 V mag/sq.arcsec) parameters of the galaxy sample. We find the following median corrected isophotal colour indices: B-Ic = 1.9 mag/sq.arcsec and V-Ic = 1.1 mag/sq.arcsec. A set of bar parameters - ellipticity, position angle, semi-major axis corresponding to the ellipticity maximum in the bar region, and length, are also reported; deprojection has been applied to the bar ellipticity, length, and relative length in terms of galaxy isophotal semi-major axis. Regarding bar length estimation, we use a method, based on the relation between the behaviour of the profiles and orbit analysis. The so estimated bar length tightly correlates with the semi-major axis, corresponding to the ellipticity maximum with a median ratio of the former to the latter of 1.22. The median of the deprojected bar ellipticity, length, and relative length are 0.39, 5.44 kpc, and 0.44, respectively. There is a correlation between the deprojected bar length and the corrected isophotal semi-major axis at 24 V mag/sq.arcsec. Three of the 17 large-scale bars appear strong, based on the deprojected bar ellipticity as a first-order approximation of bar strength. The deprojected relative bar length does not appear to correlate with the bar ellipticity.